expert-backend-allow-downgrade-ssl allows to configure each node to downgrade
SSL negotiation with the backends to insecure, OpenSSL 1 style, ciphers and
algorithms.

It's implemented only per node as it shall be only used in some specific
circumstances and the cluster default (by default) is false. Such separation
allows to setup each node independently, as it requires node restart.

backend-haproxy is hashing backend-haproxy-wrapper:output in order to be
reactive on applied change to the configuration; this will result with node
restart after the configuration.

Note that the special test backend has been moved to different file in order
to start it with subprocess with altered environment; using multiprocessing
with spawn context didn't worked out, as it altered test process and thus
supervisord environment.

This is a fixup of 61c13f54.

We need LD_LIBRARY_PATH only during OBS compilation (since the rpath is
not correctly set during compilation because it already points to final
/opt/slapos path).

This is a fixup of 61c13f54.

We must force meson to output the lib in a constant directory. Also fix
runtime libraries

This is a fixup of 61c13f54.

This is a fixup of 2fcfc506.

See merge request !1725

See merge request !1722

The registry is sending bytes.

This is a fixup of 9f0b1c97.

- Upgraded gobject-introspection to version 1.76.1:
  - Switched build system from autotools to Meson.
  - Updated pre-configure and environment variables to support Meson.
  - Removed outdated configure flags.

- Upgraded pygobject to version 3.44.2:
  - Switched build system from autotools to Meson.
  - Updated pre-configure to handle Meson subprojects.
  - Explicitly disabled cairo bindings with .
  - Updated environment variables for Meson compatibility.

See merge request !1714

Fixes handling failed backups and default_exception_handler.

See merge request !1685

Stop using deprecated ssl.wrap_socket, and let unset key-file mean
the key is included in cert-file, as is done in python ssl module.
Also let the server crash if specified cert-file or key-file does
not exist, instead of silently falling back to non-TLS http.

Add 'socketpath' and 'abstract' options for path based unix sockets
and abstract unix sockets respectively.

See merge request nexedi/slapos!1716

See nexedi/neoppod@f4a5fe3b.